Cost of illness of adult diabetes mellitus underestimated if comorbidity is not considered

OBJECTIVE: To determine costs of illness for adult diabetes mellitus (DM), including complications caused by DM. DESIGN: A population-based multicentre cross- sectional study including an interview and a physical examination of patients identified as having DM. The patients' medical records were analysed regarding diagnoses and complications attributable to DM. SETTING: Eight health care centres of six primary care districts in Southern Sweden. SUBJECTS: 1677 adults aged 25+, cared for at the health care centres, entered the study. MAIN OUTCOME MEASURES: Utilization of health care and care from relatives and the municipality, absence of short- and long-term sickness, cost of illness. RESULTS: The average annual direct and indirect costs for an adult with DM were calculated to be 61 700 Swedish Kronor (SEK) or 2.5 times higher than earlier estimates. The incremental cost of DM was 34 100 SEK. The cost distribution was 28% for health care, 31% for the municipality and relatives and 41% lost productivity. CONCLUSIONS: Calculations for the cost of illness of DM are underestimated if comorbidity caused by DM is not considered. When DM-related complications are included to identify the actual burden of disease to society, the cost of illness as a result of DM in Sweden is substantially higher than previously estimated.